Congenital anomalies of the ribs are common but rarely result in shadow which might be mistaken for pathological lesions. Careful inspection of the bony parts, which should be a routine, will usually be sufficient to avoid mistakes. Authors reviewed 6, 921(5, 865 male, 1, 056 female) chest P-A films in adult (older than 16 years), and radilographic findings of congenital anomalies of the ribs were analized. The result were as follows: 1. Congenital anomalies of to ribs were present in 193 patients. The incidence of congenital anomalies of the ribs were 2.7% in male, 3.3% in female. 2. Among the 193 cases of congenital rib anomalies, 7 cases (0.1%) of cervical ribs, 31 cases (0.4%) of underdeveloped ribs, 81 cases (1.2%) of anterior bifurcation, 34 cases (0.5%) of broadened ribs, 19 cases (0.3) of complete fusion and 21 cases (0.3%) of pseudathrosis were included. 3. 11.4% of the cases were bilateral, and right to left was 4:3 in unilateral involvement. 4. The location of the rib anomalies were as follows: (1) Underdeveloped ribs: 1st rib 31 cases (79.5%), 2nd rib 3 cases (7.7%), 4th rib 3 cases (7.7%), 5th rib 2 cases (5.1%). (2) Anterior bifurcation: 3rd rib 37 cases. 4th rib 29 cases, 5th rib 12 cases, 6th rib 6 cases, 2nd rib 2 cases. (3) Broadened ribs: 3rd rib 17 cases, 4th rib 15 cases, 5th rib 4 cases, 2nd rib 1 case. (4) Complete fusion: 1st-2nd rib 13 cases(68.4), 5-6th ribs 4 cases(21.0%), 4-5th ribs 1 case(5.3%), 6-7th ribs 1 case (5.3%). The fusion occur in the posterior portion of 1st-2nd and 4-5th ribs, and in the posterior portion of 5-6th and 6-7 ribs. (5) Pseudarthrosis: 1st-2nd ribs 15 cases(62.5%), 5-6th ribs 5 cases (20.8%), 4-5th ribs 2 cases(8.3%), 2-3 and 3-4th ribs 1 case (4.2%) each other. The paeudarthrosis occur in the anterior portion of 1st-2nd and 2nd-3rd ribs, and in the posterior portion of 3-4th, 4-5 and 5-6th ribs. 5. In the cases of anterior bifurcation, the rib bifurcates almost in its anterior 2.1-5.0 Cm and most common in 3.1-4.0 Cm. 6. The characteristic radiographic findings in anterior bifurcation were as follow: (1) The length of the involved rib is shortened(89.5%) (2) The upper branch in bifurcated from superior border of the lower rib(82.6%) (3) The portion proximal to bifurcation is broadened(62.8%) (4) The sternal extremity is poorly defined(47.7%). (5) The intercostal space is widened(47.7%). 7. 24 cases of pseudarthrosis were classified into 4 types: type II was most common(45.8%), type I 25.0%, type III 16.7% and type IV 12.5%.